Combined inlet and outlet spring loaded valves - are fitted to bung hole of barrel for emptying and pressurising

摘要

The bung is fitted on the inside with an outer cylinder (116). The cylinder fits underneath a collar (114) which is screwed into the bung. The cylinder has a glange (119) at the top end and a base (122) resting on a support (121). An inner cylinder (123) passes through the base and is held against the flange (119) by a coil spring (136) acting against the base. The inside of the cylinder has another plug (113) which is also spring loaded by a coil spring (144). The barrel may be pressurised with carbon dioxide passing through the inner valve and the fluid may be expelled from the barrel by depressing the outer valve.